This Invention discloses a method for production of N-Acetyl-D-Glucosamine and/or D-Glucosamine Salt by microbial fermentation. The method is intended to manufacture N-Acetyl-D-Glucosamine and/or D-Glucosamine Salt in higher efficiency and higher yield, by increasing the effects of N-Acetyl-D-Mannosamine Kinase.

This Invention discloses a method for production of N-Acetyl-D-Glucosamine and/or D-Glucosamine Salt by microbial fermentation. The method is intended to manufacture N-Acetyl-D-Glucosamine and/or D-Glucosamine Salt in higher efficiency and higher yield, by increasing the effects of N-Acetyl-D-Mannosamine Kinase.

In order to produce chondroitin sulfate in an animal-free manner, engineered E. coli host cells were modified so as to reduce expression of an endogenous gene for fructosyltransferase (kfoE); reduce expression of an endogenous gene for 3′-phosphoadenosine-5′-phosphosulfate reductase (cysH); and express one or more exogenous sulfotransferases. Expression of proteins forming ATP-binding cassette transporters were also reduced to limit export of glycosaminoglycans from the cells. The recombinant microorganisms are able produce all three components identified for chondroitin sulfate production—chondroitin, sulfate donor, and sulfotransferase. These modified E. coli are capable of complete, essentially one-step biosynthesis of chondroitin sulfate at a variety of sulfation levels from simple microbial media components and glucose. This is a major advantage over current production methods that depend on the natural distribution of chondroitin sulfate types in the animal tissue.

In order to produce chondroitin sulfate in an animal-free manner, engineered E. coli host cells were modified so as to reduce expression of an endogenous gene for fructosyltransferase (kfoE); reduce expression of an endogenous gene for 3′-phosphoadenosine-5′-phosphosulfate reductase (cysH); and express one or more exogenous sulfotransferases. Expression of proteins forming ATP-binding cassette transporters were also reduced to limit export of glycosaminoglycans from the cells. The recombinant microorganisms are able produce all three components identified for chondroitin sulfate production—chondroitin, sulfate donor, and sulfotransferase. These modified E. coli are capable of complete, essentially one-step biosynthesis of chondroitin sulfate at a variety of sulfation levels from simple microbial media components and glucose. This is a major advantage over current production methods that depend on the natural distribution of chondroitin sulfate types in the animal tissue.

The present invention provides a 2-OST mutant exhibiting a high activity. Specifically, the present invention provides a 2-O-sulfation enzyme mutant, having a substitution of a leucine residue at position 321 with a basic amino acid residue in any one amino acid sequence of: (a) the amino acid sequence of SEQ ID NO: 2; (b) an amino acid sequence comprising one or several amino acid substitutions, deletions, insertions, or additions in the amino acid sequence of SEQ ID NO: 2; (c) an amino acid sequence having 90% or more identity to the amino acid sequence of SEQ ID NO: 2; (d) the amino acid sequence consisting of amino acid residues at positions 69 to 356 in the amino acid sequence of SEQ ID NO: 2; (e) an amino acid sequence comprising one or several amino acid substitutions, deletions, insertions, or additions in the amino acid sequence consisting of amino acid residues at positions 69 to 356 in the amino acid sequence of SEQ ID NO: 2; (f) an amino acid sequence having 90% or more identity to the amino acid sequence consisting of amino acid residues at positions 69 to 356 in the amino acid sequence of SEQ ID NO: 2; and having a 2-O-sulfate transfer activity.

The present invention provides a 2-OST mutant exhibiting a high activity. Specifically, the present invention provides a 2-O-sulfation enzyme mutant, having a substitution of a leucine residue at position 321 with a basic amino acid residue in any one amino acid sequence of: (a) the amino acid sequence of SEQ ID NO: 2; (b) an amino acid sequence comprising one or several amino acid substitutions, deletions, insertions, or additions in the amino acid sequence of SEQ ID NO: 2; (c) an amino acid sequence having 90% or more identity to the amino acid sequence of SEQ ID NO: 2; (d) the amino acid sequence consisting of amino acid residues at positions 69 to 356 in the amino acid sequence of SEQ ID NO: 2; (e) an amino acid sequence comprising one or several amino acid substitutions, deletions, insertions, or additions in the amino acid sequence consisting of amino acid residues at positions 69 to 356 in the amino acid sequence of SEQ ID NO: 2; (f) an amino acid sequence having 90% or more identity to the amino acid sequence consisting of amino acid residues at positions 69 to 356 in the amino acid sequence of SEQ ID NO: 2; and having a 2-O-sulfate transfer activity.

The invention provides compositions and methods for engineering bacteria to produce sialylated and N-acetylglucosamine-containing oligosaccharides, and the use thereof in the prevention or treatment of infection.

The invention provides compositions and methods for engineering bacteria to produce sialylated and N-acetylglucosamine-containing oligosaccharides, and the use thereof in the prevention or treatment of infection.

The present disclosure provides an aggregation-induced emission polymer, a preparation method and application thereof. The aggregation-induced emission polymer provided in the present disclosure has a structure represented by formula I. The aggregation-induced emission polymer provided by the present disclosure has excellent fluorescence stability and biocompatibility; Because there are many benzene rings in the aggregation-induced emission polymer, the fat-solubility of the aggregation-induced emission polymer is increased, thereby changing the problem that cellulose is insoluble and difficult to be processed and modified. In the present disclosure, the aggregation-induced emission small molecule monomer is placed in a basal medium, and the bacterial seed solution is inoculated and then cultured to obtain the aggregation-induced emission polymer. The preparation method provided by the present disclosure has the characteristics of safety, environmental protection and simplicity, solves the shortcomings of complex and cumbersome synthesis process, and is beneficial to the large-scale production of AIE polymers.

The present disclosure provides an aggregation-induced emission polymer, a preparation method and application thereof. The aggregation-induced emission polymer provided in the present disclosure has a structure represented by formula I. The aggregation-induced emission polymer provided by the present disclosure has excellent fluorescence stability and biocompatibility; Because there are many benzene rings in the aggregation-induced emission polymer, the fat-solubility of the aggregation-induced emission polymer is increased, thereby changing the problem that cellulose is insoluble and difficult to be processed and modified. In the present disclosure, the aggregation-induced emission small molecule monomer is placed in a basal medium, and the bacterial seed solution is inoculated and then cultured to obtain the aggregation-induced emission polymer. The preparation method provided by the present disclosure has the characteristics of safety, environmental protection and simplicity, solves the shortcomings of complex and cumbersome synthesis process, and is beneficial to the large-scale production of AIE polymers.